How do I couple small parallel shafts offset a short distance from each other?
I have two parallel shafts, 3 millimetres in diameter and offset by 8 millimetres, both anchored in surrounding housing by ball bearings. When one shaft is rotated (via gear), I want the other shaft to rotate with it. I have less than a cubic centimetre of space between the shafts in which to place the coupling mechanism.
The first option is Oldham coupling, you say ‘ I have less than a cubic centimetre of space between the shafts in which to place the coupling mechanism.’, so i recommend Oldham coupling. They require less space in compare to the other options. Another name for Oldham is cross disc coupling (German). Friction is unavoidable, so you should consider a way to lubricate it now and then. This type of coupling is way old and they are not popular anymore in industry.
The second option is Schmidt coupling, i don’t recommend it here, because they demand much more room than Oldham coupling, and they are designed to compensate extreme radial deviations think about rolling machines.There are also some issues(start up of machines), that make the application of this type of coupling less interesting.